1. Field of the Invention
The invention relates to the field of absorbent products having reduced rewet properties, and more particularly, to an absorbent product having particular applicability to feminine hygiene products having reduced rewet properties.
2. Description of the Related Art
Traditionally, layered absorbent articles have included an inner or body facing cover of a porous fabric, an inner liquid absorbing layer or core, and an outer layer of liquid impervious film. In early products, the core was composed entirely of cellulose wadding or pulp, with the bulkiness or dry weight of the core being directly related to the maximum liquid absorption capacity.
More recently, proposals have been advanced to reduce the bulk of the core and to reduce the overall thickness of the absorbent product for several reasons, such as reduced shipping cost and storage space and better conformability of the absorbent article or garment to the body of the user. A reduced absorbent core thickness has been accomplished primarily by increasing the density of the absorbent core and by adding super-absorbent polymer, which is capable of absorbing many times its weight of liquid. These changes, however, have inevitably led to a reduction in the rate of absorption of liquid into the core, resulting in possible runoff and leakage of liquids, and the inability to completely retain the absorbed liquid.
In order to minimize the problems associated with low bulk absorbent articles, additional proposals have been made to employ a high bulk fabric as the upper layer, or to incorporate a transition layer of nonwoven fabric between the outer layer and the core. The purpose of this layer, also known as a sublayer or surge layer, is to hold or retain excess liquid for a time sufficient to allow the core to permanently absorb the liquid.
Various types of fabrics have been used as sublayers, including low density lofty fabrics having a high liquid void volume. These lofty fabrics typically have a porosity of greater than 97 percent and are made from through-air thermally bonded bicomponent fibers to provide a sublayer having a high void volume. Airformed wood pulp also has been used as sublayer material. Traditionally, the topsheets of layered absorbent articles are formed from polymeric fabrics, such as polypropylene and polyethylene spunbonded fabrics. Such topsheets may also comprise an apertured material having openings extending from the surface of the material to the sublayers. Such fabrics are known in the art.
In view of the foregoing considerations, there is a continuing need to provide layered absorbent articles of the compact type that not only are capable of retaining liquid insults to be absorbed by the core, but also are capable of providing good separation and a significantly reduced amount of liquid rewet to the top sheet.
The present invention relates to a novel compact absorbent product that has been found to provide optimal absorbency while simultaneously decreasing the amount of rewet when compared to other absorbent products. The absorbent product is a unique combination comprising a topsheet, a secondary absorbent layer, a primary absorbent layer and a backsheet. The topsheet is apertured and has a relatively high loft while also having a relatively low open area. The topsheet preferably aids in the fluid flow through the topsheet to the secondary absorbent layer. The secondary absorbent layer absorbs the fluid and preferably acts as a holding reservoir until the primary absorbent layer can absorb the fluid held in the secondary absorbent layer.
These and other features and advantages of this invention will become evident from the following description of the preferred embodiments of this invention, with reference to the accompanying drawings.